Dokdonia donghaensis gen. nov., sp. nov., isolated from sea water

Two Gram-negative, non-motile, non-spore-forming, slightly halophilic bacterial strains, DSW-1^T and DSW-21, were isolated from sea water and subjected to a polyphasic taxonomic study. They grew optimally at 30 °C and in the presence of 2 % (w/v) NaCl. Strains DSW-1^T and DSW-21 were characterized chemotaxonomically as containing MK-6 as the predominant menaquinone and iso-C_15:0, iso-C_17:0 3-OH and iso-C_15:1 as the major fatty acids. Their DNA G+C content was 38 mol%. Strains DSW-1^T and DSW-21 exhibited four nucleotide differences in their 16S rRNA gene sequences and possessed a mean DNA-DNA relatedness level of 78 %. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strains DSW-1^T and DSW-21 formed a distinct lineage within the family Flavobacteriaceae. The 16S rRNA gene sequences of strains DSW-1^T and DSW-21 had similarity levels of less than 92.2 % to the sequences of other members of the family Flavobacteriaceae. There were some differences in phenotypic properties between the two strains and Cellulophaga species, the nearest phylogenetic neighbours. On the basis of phenotypic, phylogenetic and genetic data, strains DSW-1^T (= KCTC 12391^T = DSM 17200^T) and DSW-21 were classified in a novel genus and species, Dokdonia donghaensis gen. nov., sp. nov.